"Three timelines converge to unveil the mysterious disappearance of two girls during World War II"-- Provided by publisher.

"You would like me to tell the story... New York City, 2020. As the world stills around them, best friends Miles and Chloe keep each other afloat with late-night phone calls and true-crime podcasts. When an unexpected package from Chloe's grandmother arrives, it plunges them into their own cold-case investigation: two unidentified teenagers who went missing in a German forest eighty years ago. What if the story I need to tell is not the one you want to hear? West Berlin, 1980. In a divided Germany, under the strict eyes of her parents, lonely American transplant Jenny is suffocating. Until she meets free-spirited Lena, a beautiful punk-rock girl hellbent on tearing down the Berlin Wall, and the mysterious Frau Hermann, a kind old lady whose fascinating stories may hide secrets of her own. Very well. It begins the same: once upon a time... Kleinwald, Germany, 1939. It is said that if you write a letter to the Bridegroom's Oak, the love of your life will answer back. The summer that best friends Sophie and Hanna receive their first replies from the famous tree, the world suddenly feels like a pliable, magical thing, as if it could be shaped by their dreams. But soon, World War II creeps into their small town. Dreams turn brittle, neighbors turn on one another, lies bloom like poppies between the girls, and the forest is no longer a refuge but a dark wood, filled with unimaginable danger. When the Bridegroom's Oak gives up its secrets at last, Miles and Chloe discover the uncomfortable weight of truth, the worth of reconciliation, and what must be sacrificed for a better world. From New York Times-bestselling and Printz Award-winning author Libba Bray comes an evocative, propulsive, century-spanning mystery that examines the cyclical nature of fascism and genocide -- and how young people have always been part of the resistance against them." -- Jacket flap.